One-way overrunning clutch

ABSTRACT

An overrunning clutch assembly including first and second ring-shaped clutch members with face surfaces disposed in opposing relation and with at least one rigid strut disposed therebetween for movement to engage recessed pockets in the opposed surfaces upon rotation in one direction and for movement out of engagement with the pockets in at least one of the face surfaces upon relative rotation in the opposite direction. A retaining member permanently retains the clutch in assembled relation and cooperates with the ring-shaped clutch members to form a lubricant reservoir maintaining the struts in a lubricant bath during operation. The retaining member forms a weir over which the lubricant flows from the reservoir at a radial location to assure that the struts remain submerged during operation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to one-way drive, overrunning clutch mechanisms,and more particularly to an improved lightweight, one-way clutch ofsimplified construction and high torque transmitting capability which isespecially well adapted for high speed operation.

2. Description of the Prior Art

One-way drive overrunning clutch mechanisms, hereinafter generallyreferred to as clutches, or as overrunning clutches, are well known andwidely used in a variety of applications ranging from low speed devicessuch as bicycle drives to high speed mechanisms such as automotivetransmissions and torque converters. Commercial clutches employed inhigh speed automotive transmissions have in the past generally been ofthe sprag-type or the roller-ramp type, both of which depend on awedging action to lock up, or to transmit torque between the driving anddriven members of the clutch. The wedging action of these clutchesproduces extremely high stresses in component parts, and the clutchesare relatively heavy and expensive to manufacture. Such clutchesgenerally are considered the weakest link in an automatic transmission.

Clutches are also known which employ rigid struts positioned between thedriving and driven clutch members, or clutch plates, for pivotalmovement between a driving position engaging shoulders defined bynotches in the driving and driven clutch plates to transmit torquetherebetween upon relative rotation in one direction and to permitoverrunning, or free wheeling, upon relative rotation in the oppositedirection. Clutches of this type are disclosed, for example, in U.S.Pat. Nos. 5,070,978 and 5,449,057.

In the typical strut-type clutch, the individual struts are mounted forpivotal movement between a driving position in which opposed ends, oropposed edges of at least one strut engages a shoulder formed by notchesin closely spaced, opposed faces of the driving and driven clutch platesupon rotation of the driving member in one direction and a retractedposition in which the struts are out of engagement with at least one ofthe clutch plates when the driving member is rotated in the oppositedirection relative to the driven member. The struts may be pivotallymounted on a carrier disposed between the clutch faces as in U.S. Pat.No. 5,449,057, but in most commercial drives of this type, the strutsare carried in a pocket in one clutch plate face with one end or edgecontinuously contacting a shoulder defined by the pockets. Whethersupported by a carrier or mounted in a pocket in one of the clutchfaces, the individual struts are continuously urged to a position toengage both clutch faces by a resilient member, typically a spring, tothereby lock the two clutch plates together upon rotation of the drivemember relative to the driven member in one direction. Upon relativerotation in the opposite, or overrunning direction, the spring memberscontinue to urge the struts into contact with the clutch faces and tendto urge the struts into each of the pockets as they are rotated, withthe shape of the pockets camming the struts back as rotation continues.

As suggested in the above-mentioned U.S. Pat. No. 5,449,057, theprevious overrunning clutches used in high speed transmission mechanismshave required a continuous supply of lubrication to assure that thestruts, sprags, or rollers are continuously coated to minimize wear,particularly when the clutch is operated in the overrunning mode. Whensuch clutches are employed in mechanisms such as automatic transmissionscontaining a reservoir of lubricant which is continuously splashedthroughout the interior of the mechanism by the various rotatingcomponents, this more or less random distribution of lubricant has beenrelied upon to lubricate the clutches. It has been discovered, however,that such systems do not always provide adequate lubrication to minimizewear and to enable the most efficient operation, especially in theoverrunning mode.

It has been shown that pivotal movement of the struts of strut-typeclutches can be effectively damped at high speeds by maintaining thestruts submerged in a bath of lubricating oil so that they remainessentially stationary in the overrunning mode. This substantiallyeliminates rapid depression and expansion of the resilient springmembers engaging each strut as the strut passes over the respectiverecesses in the adjacent clutch face and thereby greatly increases thespring life by effectively eliminating fatigue failures. Further, bymaintaining the struts substantially fully submerged in a bath oflubricating oil during all high speed operations, direct metal-to-metalcontact between the struts and clutch faces is avoided by the continuouscoating of lubricant.

The above-mentioned U.S. Pat. No. 5,070,978 discloses the concept ofproviding a housing, with seals between the housing and input shaft, toenclose the clutch plates. The sealed housing is filled with oil toassure continuous lubrication to "float" the two opposed clutch platesaway from one another during free wheeling or overrunning. This patentalso seems to recognize, at column 8, lines 10-12, that filling thehousing with oil may have an effect on strut movement during overrunningat high speed, although the patent also states that the struts "hardlymove at all" at high speeds even without filling the housing with oil.The housing comprises a generally cup-shaped, output shell having anopen end which is closed by a threaded closure plate. The use of aseparate housing and threaded closure greatly increases the cost of theclutch, and presents the potential for failure in the event of thethreading connector becoming loose during prolonged use. Further, noprovision is made for replenishing the oil supply in the event of sealfailure, thereby presenting the potential for excessive wear,overheating and eventual failure of the clutch in the event of oilescaping from the sealed housing. The sealed housing would act as ashield effectively preventing splashed oil from reaching the struts inthe event of seal failures. Further, the separate housing and threadedclosure greatly increases the overall weight and size of the clutchassembly.

Accordingly, it is an object of the present invention to provide animproved lightweight strut-type overrunning clutch assembly havingimproved means for assuring continuous lubrication for the clutchcomponents.

Another object is to provide such a clutch assembly which assures thatthe movable struts are continuously submerged in a reservoir of oilduring high speed operation regardless of the attitude of the mechanismin which the clutch is used.

Another object is to provide such a clutch assembly having an improvedlightweight retaining means retaining the clutch plates in assembledrelation and providing an oil-tight joint with one of the clutch membersand serving as a weir or dam to retain a reservoir of oil under pressurefrom centrifugal force between the clutch plates and enveloping thestruts and spring members during high speed operation.

Another object is to provide such a clutch assembly including means forproviding a continuous flow of oil through the clutch assembly duringoperation.

Another object is to provide such a clutch assembly which is lessexpensive to manufacture and which is highly reliable in operation.

SUMMARY OF THE INVENTION

The foregoing and other objects and advantages are achieved inaccordance with the present invention in which a plurality of rigidstruts are disposed between adjacent, opposed, relatively rotatablefaces on a pair of clutch plates for pivotal movement between an engagedposition in which at least one strut is rotated to a position engaging ashoulder on both clutch faces to thereby interlock the two clutch platesfor rotation together about a common axis in one direction, and adisengage or overrunning position permitting free relative rotation ofthe clutch plates in the opposite direction. The first clutch plate hasan axially extending outer rim portion and a radially inwardly extendingintegrally formed body portion at one end of the outer rim portion. Thesecond clutch plate also has a substantially radially extending bodyportion having an outer periphery telescopingly received in the axiallyextending rim portion of the first clutch plate and preferably has anintegrally formed axially extending inner hub telescopingly received inthe inner periphery of the first clutch plate with the first and secondclutch plates cooperating to define a cavity therebetween. A pluralityof struts are mounted in the cavity between the first and second clutchplates for pivotal movement between the engaged or driving position anda disengaged or overrunning position. In the preferred embodiment of theinvention, the clutch faces are generally flat parallel annular clutchsurfaces similar to the arrangement shown in the above-mentioned U.S.Pat. No. 5,070,978 and in FIGS. 15-27 of copending application Ser. No.08/382,070, now U.S. Pat. No. 5,597,057.

In the preferred embodiments, the annular rim on the first clutch plateextends axially beyond the body portion of the second clutch plate, andan inwardly directed annular groove is formed in the outer rim portionof the first clutch plate at a location outboard of but immediatelyadjacent to the body portion of the second clutch plate member. Anannular retainer is rigidly fixed in the annular groove and overlyingthe surface of the second clutch plate to firmly retain the first andsecond clutch plates in assembled relation. The retainer preferably isinitially formed as a continuous annular ring of metal which has a bodyportion shaped into a generally frustoconical or Belleville washerconfiguration, and which is then press formed into a substantially flat,planar configuration to expand its outer periphery into the annulargroove and to overlie and engage the radially extending body portion ofthe second clutch plate.

The annular groove and the outer peripheral portion of the retainer aredimensioned such that, upon installing the retainer, the groove engagesand swages the retainer edge to conform to the groove geometry and forma fluid tight seal. The inner periphery of the retainer extends radiallyinward to a location at least substantially equal to the location of theradial innermost part of the rigid struts but outboard of the innerperiphery of the body portion of the outer clutch plate. The radiallyinwardly extending body portion and the outer rim portion of the firstclutch plate member and the retainer cooperate to form a generallytoroidal, inwardly open enclosure or annular trough surrounding thecavity between the two clutch plates and the outer peripheral portion ofthe second clutch plate.

An oil supply passage is provided to deliver lubricating oil into thecavity between the opposed clutch faces to provide lubrication for thecomponent parts and to essentially fill the cavity between the clutchfaces. Upon rotation of the clutch, centrifugal force acting on thelubricating oil will retain the oil in the toroidal space; thus, as soonas this space is filled with lubricating oil, it will remain filled andunder pressure for so long as the clutch continues to rotate at a speedsufficient for the centrifugal force to overcome the force of gravity,regardless of the orientation of the clutch.

centrifugal force will cause the oil to flow between the outer peripheryof the second clutch plate body portion and the first clutch plate rimportion, then along the retainer to flow over the edge of the retainerwhich acts as a weir, assuring that the struts are continuouslysubmerged in a body of pressurized lubricating oil. Preferably, theinner periphery or hub of the second clutch plate and the outer rimportion of the first clutch plate are formed with splines, or gear teethfor cooperating with mating splines or gear teeth on a driving anddriven member for the transfer of power upon rotation in one directiononly. In a preferred embodiment, oil may be supplied through a drilledpassage in a mounting shaft or gear to an annular oil ring communicatingwith the cavity between the first and second clutch faces as by adrilled oil passage formed in the second clutch plate hub.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the invention will beapparent from the detailed description contained hereinbelow, taken inconjunction with the drawings, in which:

FIG. 1 is an elevation view of a clutch assembly according to thepresent invention;

FIG. 2 is an exploded view of the clutch assembly shown in FIG. 1, withcertain parts being omitted for clarity;

FIG. 3 is a sectional view taken on line 3--3 of FIG. 1, with certainelements shown to a different scale for clarity;

FIG. 4 is an enlarged fragmentary sectional view of a portion of thestructure shown in FIG. 3;

FIG. 5 is a fragmentary sectional view taken on line 5--5 of FIG. 4;

FIG. 6 is a view similar to FIG. 5 and showing the clutch in anoverrunning condition;

FIG. 7 is a perspective view, on an enlarged scale, of a rigid strutemployed in the clutch;

FIG. 8 is a sectional view showing the clutch in partially assembledrelation with the rigid retainer in position to be installed;

FIG. 9 is a view similar to FIG. 8 and showing a die member forinstalling the rigid retainer;

FIG. 10 is a view similar to FIG. 9 showing the retainer partiallyinstalled;

FIG. 11 is a view of the fully assembled clutch with the die illustratedin final assembly position;

FIG. 12 is an enlarged fragmentary sectional view of an alternateembodiment of the invention with the seal in position to be installed;

FIG. 13 is a view similar to FIG. 4 and showing the clutch components ofFIG. 12 in the fully assembled condition; and

FIGS. 14-16 are fragmentary sectional views, each showing a furtherembodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings in detail, a clutch assembly according tothe present invention is indicated generally by the reference numeral 10and includes an outer clutch member or clutch plate 12 and an innerclutch member or clutch plate 14. The clutch 10 is illustrated in FIG. 3as mounted on a driven shaft 16 and supported against rotation thereonby gear teeth 18 on the inner periphery of clutch plate 14, which gearteeth mate with splines 20 on the outer periphery of shaft 16.

The outer clutch plate 12 includes a ring shaped body portion 22 havinga cylindrical inner peripheral surface 24 and a planar, annular innersurface 26, and an outer rim portion 28 extending axially from planarinner surface 26. Gear teeth, or splines 30, are formed around the outerperiphery of outer rim portion 28 for engaging with mating gear teeth ona drive gear, not shown.

The inner clutch plate 14 also includes a generally ring shaped bodyportion 32 having a cylindrical outer peripheral surface 34 dimensionedto fit closely within the cylindrical inner surface 36 of outer rimportion 28 and has on its inner peripheral portion an axially extendinghub 38 having an outwardly directed cylindrical surface 40 dimensionedto telescopingly receive the inner peripheral surface 24 of the outerclutch plate 12. The inner clutch plate's body portion 32 also has aplanar inner surface 42 disposed in closely spaced, parallel relation tothe outer clutch plate's planar inner surface 26 when the clutch isassembled.

The planar inner surface 26 of outer clutch member 12 has a plurality ofrecesses 44 formed therein with each adapted to receive a strut or key46. Each recess 44 further includes a secondary recess 48 for receivinga spring 50.

As best seen in FIG. 7, the key 46 includes a rigid, generallyrectangular body 52 with laterally extending wings 54 projecting onefrom each side edge 56 of the body adjacent one end thereof. The frontend of body 52, i.e., the end opposite the end having wings 54 formedthereon, may be a substantially, flat planar surface inclined slightlywith respect to the opposed planar surfaces of body 52, but preferablyis slightly curved, as shown at 58 in FIG. 7. The back end 60, i.e, theend opposite and generally parallel to end 58 is a flat planar surfaceinclined with respect to the faces of body 52 at an angle generallycorresponding to the angle of inclination of the end 58. The angle ofinclination of the ends 58, 60 corresponds to the maximum angle ofinclination or movement of the key from the engaged or driving positionprojecting into a recess 44 as shown in FIG. 5 and the retracted oroverrunning position withdrawn from the recess 44 as shown in FIG. 6.

The planar annular surface 42 of inner clutch plate 14 is provided witha plurality of key-engaging notches 62 providing a ring of abutmentfaces or shoulders 64 in position to be engaged by the end 58 of one ofthe keys 46 in the driving mode. Notches 62 may have a sloped orinclined rear portion 66. As stated above, the front end 58 may be aflat planar surface but preferably is slightly arcuate, with the degreeof curvature being exaggerated in FIG. 7 for illustrative purposes. Whenthe end 58 is arcuate, the shoulders 64 will also be correspondinglycurved so that, in the engaged position, the ends 58 and shoulders 64will be in contact along the full length of end 58. At the same time,the slightly arcuate configuration permits sufficient adjustment ormovement of the key, under load, to accommodate any slight misalignmentwhich might occur due to manufacturing tolerances, thereby eliminatingor minimizing stress concentrations which could be produced as a resultof such misalignment. Also, as seen in FIGS. 5-7, the wings 54preferably are provided with an inclined ramp portion 68 to permit freetilting of the key, under influence of the springs 50 to project thebody 52 into a recess 44 as shown in FIG. 5. To facilitate the free flowof lubricating oil into the recesses 44 and subrecesses 48, each recess44 preferably includes a relief 70 and a similar relief 72 is preferablyformed at one end of each subrecess 48.

As thus far described, the structure of the clutch assembly, includingthe outer clutch plate 12, the inner clutch plate 14, the driving keys,and the resilient springs, may be substantially identical to thatdisclosed and described in copending application Ser. No. 08/382,070 nowU.S. Pat. No. 5,597,057, with the single exception of the preferredarcuate configuration of the key end 58 and the driving notch shoulder64.

As in the clutch assembly described in the above pending application,when the outer clutch plate 12 is rotated in the driving direction,i.e., to the right in FIG. 5, the spring 50 will urge the key 46 intothe notch 62 so that the front end 58 of one key 52 will engage theshoulder 64 of that notch 62. Resistance to movement of the inner clutchplate 14 acting through the key end 58 and shoulder 64 will tend to camthe key into full engagement with the shoulder, thereby assisting thespring 50 in projecting the key fully into the notch.

When the outer clutch plate 12 is rotated in the opposite direction,i.e., to the left in FIG. 6, or when the inner clutch plate 14 tends torotate faster than the outer clutch plate 12, the inclined surface 66 ofnotch 62 will cam the key back into the recess 44 to the overrunningposition. In this overrunning condition shown in FIG. 6, it is desirablethat the recesses 44, subrecesses 48, and notches 62 be completelyfilled with a lubricating oil to dampen movement of the keys assuccessive notches 62 pass over the respective keys, thereby preventingthe springs 50 from projecting the keys into the notches only to bedriven back by impact with the inclined notch surfaces 66. In accordancewith the present invention, this supply of pressurized oil completelysubmerging the body 52 of each key is assured during normal operation ofthe clutch assembly.

Referring now to FIGS. 3 and 4, it is seen that the outer rim portion 28of the outer clutch plate 12 is provided at its open end with acounterbore providing a cylindrical surface 74 having a diameter greaterthan the diameter of cylindrical surface 36 and terminating in a planarannular shoulder 76 lying in a plane parallel to the planar innersurface 26. A generally V-shaped annular groove or notch 77 is formed inthe cylindrical wall 74 adjacent the shoulder 76, and a retainer 78 ispressed into and forms a fluid-tight seal with the groove 77 around itsentire periphery. In the preferred embodiment of the invention as shownin FIGS. 1-11, the retainer as initially formed (see FIG. 8) has agenerally frustoconical ring-shaped body portion 80 having an annularinner peripheral edge 82 and a generally axially extending flange 84integrally formed on its outer edge. The outer diameter of flange 84 isgreater than the diameter of cylindrical surface 36 and slightly lessthan the diameter of cylindrical surface 74.

As shown in FIGS. 8-11, the generally frustoconical retainer 78 isinitially positioned in the counterbore 74 with the flange 84 adjacentthe V-shaped groove 77 and with the frustoconical body portion 80 havingits inner peripheral edge 82 projecting outwardly from the end of hub38. The inner peripheral edge 82 of the retainer is then engaged by ashoulder 86 on an axially movable die element 88 which is moved downwardto compress the retainer and form its major diameter outwardly and intothe V-shaped groove 77. Final movement of the die 88 conforms theaxially extending flange portion 84 of retainer 78 firmly into thegroove 77 and shapes the body portion 80 into a planar substantially,annular ring overlying the outer surface 90 of inner clutch plate 14.

During press forming of the retainer 78, the inner periperal edge isretained against radial shrinking by the shoulder 86 on die 88. Also,during the final movement of die 88, an annular notch 92 engages the endof flange 84 to swage the retainer to conform to the geometry of thegroove 77 and form a fluid tight seal therewith.

The minor diameter of the retainer, in the installed position, extendsradially inward to a position at least overlying the body 52 of the keys46 but radially outboard of the outer clutch plate's inner peripheralsurface 24. Thus, the retainer 78, the outer rim portion 28, and thebody portion 22 of the outer clutch plate 12 define, in effect, agenerally toroidal-shaped, annular cavity containing the keys 46,springs 50, the recesses 44 and subrecesses 48, as well as the notches62 formed in the planar inner surface 42 of the inner clutch plate 14.

Referring again to FIGS. 3 and 4, it is seen that an oil supply passage94 extends through the hub 38 and terminates at the intersection ofsurfaces 42 and 40. Oil, under pressure, may be supplied to the passage94 through oil supply passages 96, 98 in shaft 16. Although in thestatic position as shown in FIG. 3, the planar inner surfaces 26 and 42may be in direct contact, the clutch plates are dimensioned so as toprovide some finite clearance between these surfaces during operation sothat a film of oil will be present and oil can flow from passage 94between these surfaces and into the recesses 44 and 48 and the notches66. The separation of surfaces 26 and 42 is shown somewhat exaggeratedin FIGS. 4-6 to illustrate the oil flow passage. Also, a film of oilwill be present between opposing cylindrical surfaces 24 and 40 as wellas between cylindrical surfaces 34 and 36 to permit restricted flow andto provide lubrication and avoid direct metal-to-metal contact of thesesurfaces during operation.

During high speed operation, oil in the recesses and notches willsurround the keys 46 and be pressurized both by centrifugal force andthe pressure of oil flowing through passage 94 from passages 96, 98 andwill cause a continuous flow of oil into and through these recesses andnotches, and outwardly between surfaces 34 and 36 and along the opposingouter surface 90 of inner clutch plate 14 and the inner surface 91 ofthe retainer 78. The inner peripheral edge 82 of retainer 78 extendsalong surface 90 to a position radially between the hub 38 and theradially inner portion of the body 52 of keys 46 and acts as a weir topermit a continuous restricted outward flow of lubricating oil over edge82 while maintaining the keys submerged in oil during operation.

Since the retainer 78 is rigidly and permanently fixed in the V-shapedgroove 77, and forms a fluid-tight seal therewith, the clutch plates12,14 are continuously maintained in a fixed, spatial relation, with acontinuous supply of lubricating oil to all opposing relatively movingsurfaces during normal operation. The permanent, interlockedpressure-formed joint between the retainer and the V-shaped notchassures against channeling of lubricating fluid and/or the loss of fluidas a result of improper fitting or loosening of conventional resilientsnap ring or threaded retainers of the type employed in the past.

The retaining element 78 is preferably initially stamped and formed froma flat sheet of a suitable steel material as an annular ring which isshaped into the frustoconical configuration having its outermostperipheral edge portion rolled into a configuration to be pressureformed into and form a seal with the groove 77.

While only a single oil passage 94 is shown in the drawings, it shouldbe apparent that a plurality of such passages may be provided ifdesired. For example, a plurality of such oil passages may be providedat spaced intervals around the inner periphery of hub 38, with oilsupply being provided to each from oil passage 96, 98 in shaft 16communicating with an annular groove (not shown) extending around theshaft so that each such oil passage 94 will be in continuouscommunication with a supply of oil under pressure during operation.Alternatively, of course, multiple radially extending oil passages 98might be provided, one in communication with each such passage 94.

In operation of a clutch constructed substantially as described above,with the inner and outer clutch plates being formed from a transparent,thermoplastic material, it has been shown that lubrication filling thevoid space between the clutch plates 12 and 14 and maintained underpressure produced from centrifugal force, will substantially completelydampen all movement of the keys 46 when the clutch is in the overrunningmode. A high speed camera operating at 20,000 frames per second used tophotograph the keys when operating in the overrunning mode showed thatno visibly discernible movement of the keys was present at speeds aboveabout 150 rpm. In this experimental clutch formed from synthetic resinmaterial, the outside diameter of the outer clutch member 12 was 6inches, and the radial distance from the center of the shaft to theoutside edge 56 of the keys was 2.5 inches.

Referring now to FIGS. 12 and 13, an alternate embodiment of theinvention will be described. In this embodiment, the outer and innerclutch plates, keys and springs are substantially identical to thatdescribed above and the same reference numerals are employed herein todesignate similar parts. In this embodiment, however, the retainer isinitially formed as a frustoconical ring 100 having a substantiallyuniform thickness throughout. The configuration of the inwardly directedgroove 102 formed in the counterbore portion of outer rim portion 28 hasa more shallow V configuration than in the previously describedembodiment. As shown in FIG. 13, the outer peripheral edge 104 of theretainer 100 is expanded into the groove 102 and swaged into theconfiguration of the groove by the pressing movement forming theretainer into a substantially flat, planar ring in the manner describedhereinabove. Once installed, the clutch assembly is permanentlyassembled, with the inner peripheral edge thereof acting as a weir inthe same manner described above.

FIG. 14 illustrates a modification of the structure shown in FIGS. 12and 13 in which the retainer 110 is provided around its inner peripherywith a reinforcing or stiffening bead, or flange 112, prior to beingpress formed into the assembled relation overlying the outer surface 90of inner clutch plate 14. The reinforcing bead 112 provides stiffnessand dimensional stability of the retainer 110 and tends to maintain theinner peripheral portion of the planar body of the retainer member in amore flat or plane condition after installation. It is understood thatsuch a reinforcing bead or flange could readily be provided on theembodiment shown and described above with reference to FIGS. 3 and 4.

FIG. 15 illustrates an embodiment wherein the retainer 120 is in theform of a rigid, flat washer or ring which is fitted into thecounterbore 74 of outer clutch plate 12 to rest upon the shoulder 76.The outer clutch plate 12 may be identical to that described above withrespect to FIGS. 3 and 4; however, as illustrated in FIG. 15, theV-shaped notch in the cylindrical wall of the counterbore is preferablyeliminated. In this embodiment, the retainer 120 is rigidly retained inposition overlying the outer surface 90 of inner clutch plate 14 by acontinuous bead 124 of the material formed from the outer rim portion 28of the outer clutch plate 12 which is deformed by a known pressingoperation in which force is applied to the end of outer clutch plate 12adjacent the counterbore 74. As a further alternative, the bead 124 maybe replaced with a succession of tabs (not shown) formed by a stakingoperation to deform metal from the outer rim portion 28 of outer clutchplate 12 at spaced intervals around the periphery of the retainer 120.In this staked configuration, the outer diameter of the retainer 120 andthe inner diameter of the counterbore are preferably dimensioned toprovide a press fit with sufficient interference to form a reliablefluid seal to substantially prevent leakage of oil between the outerdiameter of the retainer 120 and the counterbore formed in the end ofouter clutch plate 12. A similar interference fit may also be employedwhere a continuous bead 124 of material is deformed as illustrated inFIG. 15.

A further modification of the invention is illustrated in FIG. 16wherein the axially extending inner hub (designated at 38 in theembodiment illustrated in FIGS. 3 and 4) has been eliminated. In thisembodiment, outer and inner clutch members 132, 134, respectively, havetheir opposing inner faces formed with a tapered, or bevelled surface134, 136, respectively, cooperating to provide a generally V-shapedannular channel 138 around the inner periphery of the clutch assembly.The channel 138 is positioned, in operation, in substantially opposedrelation to the discharge outlet of the lubricant channel 98 in shaft 16whereby, upon rotation of the assembly, lubricant discharged fromchannel 98 will either be discharged from outlet channel 98 undersufficient pressure or be propelled by its own momentum and theinfluence of centrifugal force, into the channel 138. From the channel138, oil flows under influence of centrifugal force between the opposingsurfaces 26 and 42 and through the recesses 44, 48, and over thesurfaces of the keys 52 to be discharged over the inner periphery of theretaining member, acting as a weir, in the same manner describedhereinabove.

The embodiment of FIG. 16 is illustrated as employing the retainingelement of the same configuration shown in FIG. 14. It is believedapparent, however, that any of the other configurations of the retainingelement may be employed with this embodiment.

In each of the embodiments described above, the two ring-shaped clutchmembers and the retainer cooperate to form a generally toroidal,inwardly open enclosure or annular trough defining a lubricant flow pathextending radially outward between the two clutch members and over thestruts or keys, then radially inward between the second clutch memberand the retainer. The location of the inner periphery of the retainerenables it to act as a weir for the discharge of lubricant to assurethat the struts or keys are continuously submerged during operation. Thecontinuous flow of lubricant acts as a coolant and to flush any foreignmatter from the clutch as well as to dampen movement of the struts orkeys in the overrunning mode.

While preferred embodiments of the invention have been illustrated anddescribed, it is believed apparent that various modifications might bemade and it is therefore intended to include all of the embodimentswhich would be apparent to one skilled in the art and which come withinthe spirit and scope of the invention.

What is claimed:
 1. A one-way overrunning clutch assembly comprising:afirst clutch member including an annular body portion having acylindrical inner periphery and an outer periphery defined by an annularrim portion projecting axially from a first side thereof, said rimportion having an inner cylindrical surface; a second clutch memberincluding an annular body portion having a cylindrical outer surface andan inner peripheral surface, the cylindrical outer surface of the bodyportion of the second clutch member being telescopingly received in theinner cylindrical surface of the rim portion of said first clutch membersuch that said first and second clutch members have a common centralaxis; said first and second clutch members having inner surfacesdisposed in spaced opposing relation to one another, each inner surfacehaving a plurality of recesses formed therein to define strut abutmentshoulders at spaced intervals thereabout; a rigid strut having a bodyportion pivotally supported for movement between a driving position,wherein said strut projects into and engages an abutment shoulder in theinner surface of each of said clutch members to interlock said clutchmembers for rotation together in one direction, and an overrunningposition, wherein said strut is out of contact with the abutmentshoulders of the inner surface of at least one of said clutch members topermit free relative rotation between said first and second clutchmembers in the opposite direction; and an annular retainer positionedwithin the inner cylindrical surface of the rim portion of said firstclutch member, said retainer having an outer peripheral edge portionpermanently engaging and forming a fluid-tight seal with the cylindricalinner surface of the rim portion of said first clutch member and anannular body portion having a first surface overlying at least a portionof the body portion of said second clutch member, the annular bodyportion of said retainer extending inward from the inner cylindricalsurface of the rim portion of said first clutch member and terminatingin an inner peripheral edge defining an annular weir at a radiallocation between the radially-innermost portion of the body of saidstrut and radially outward from the inner periphery of said first clutchmember.
 2. The clutch assembly defined in claim 1, further including acounterbore formed in the rim portion of said first clutch member, thecounterbore terminating in a shoulder spaced axially from the innersurface of said first clutch member, the shoulder engaging said retainerto axially fix said retainer relative to the rim portion of said firstclutch member.
 3. The clutch assembly defined in claim 2, wherein theinner surfaces of said clutch members are substantially planar.
 4. Theclutch assembly defined in claim 2, further including an annular grooveformed in the rim portion of said first clutch member within thecounterbore at a location adjacent to the shoulder thereof, the outerperipheral edge portion of said retainer projecting into the groove. 5.The clutch assembly defined in claim 4, wherein said retainer isinitially formed with a generally axially-extending flange around theouter peripheral edge portion thereof, and wherein the outer peripheraledge portion of said retainer is mounted in the groove by a pressingoperation which radially expands said retainer, the flange beingdeformed radially inward by contact with the groove during the pressingoperation.
 6. The clutch assembly defined in claim 5, wherein saidretainer includes a reinforcing bead or flange formed around the innerperipheral edge thereof.
 7. The clutch assembly defined in claim 6,wherein the inner surfaces of said clutch members are substantiallyplanar.
 8. The clutch assembly defined in claim 2, wherein said retainercomprises a planar, annular washer having an outer cylindrical surfacereceived within the counterbore of said rim portion and having a second,generally planar surface engaging shoulder, and wherein a portion of thematerial forming the rim portion of said first clutch member is deformedto engage said retainer on a second planar surface thereof opposite thefirst planar surface to thereby permanently retain said washer withinthe counterbore of the rim portion of said first clutch member.
 9. Theclutch assembly defined in claim 8, wherein the outer cylindricalsurface of the retainer is in an interference fit with the counterboreof the rim portion of said first clutch member.
 10. The clutch assemblydefined in claim 1, wherein the inner surfaces of said first and secondclutch members are substantially flat surfaces defining a cavitytherebetween, and wherein at least one of said clutch members includes alubricant-receiving channel communicating with said cavity, whereby oilsupplied to said channel will flow between the inner surfaces of saidclutch members under influence of centrifugal force during operation ofthe clutch assembly.
 11. A one-way overrunning clutch assemblycomprising:a first clutch member including an annular body portionhaving a cylindrical inner periphery and an outer periphery defined byan annular rim portion projecting axially from one side thereof, the rimportion of said first clutch member having an inner cylindrical surface;a second clutch member including an annular body portion having acylindrical outer surface and an inner periphery defined by a hubprojecting axially from one side thereof, the hub having an outercylindrical surface, the cylindrical inner periphery of the body portionof the first clutch member being telescopingly received on the outercylindrical surface of the hub of said second clutch member, and thecylindrical outer surface of the body portion of the second clutchmember being telescopingly received in the inner cylindrical surface ofthe rim portion of said first clutch member, whereby said first andsecond clutch members define an enclosed cavity therebetween; said firstand second clutch members having substantially planar inner surfacesdisposed in opposing relation to one another, each inner surface havinga plurality of recesses formed therein to define strut abutmentshoulders at spaced intervals about the respective inner surfaces; atleast one rigid strut having a body portion pivotally supported formovement between a driving position, characterized by a strut projectinginto and engaging an abutment shoulder of each of said clutch members tointerlock said clutch members for rotation together in one direction,and an overrunning position, characterized by a strut being out ofcontact with the abutment shoulders of at least one of said clutchmembers to permit free relative rotation between said first and secondclutch members in the opposite direction, each strut having aradially-innermost portion; an inwardly-directed annular groove formedin an inner surface of the rim portion of said first clutch member; andan annular retainer having an outer peripheral edge portion permanentlyengaged and forming a fluid-tight seal with the groove in the rimportion of said first clutch member and a body portion overlying aportion of said second clutch member, the body portion of said retainerextending inward from the groove and terminating in an inner peripheraledge at a location radially inward of the radially-innermost portion ofthe body portion of said at least one strut and radially outward of thecylindrical outer surface of the hub of the second clutch member. 12.The clutch assembly defined in claim 11, including an oil passage formedin and extending through said second clutch member and communicatingwith said cavity at a location radially inward of the inner peripheraledge of said retainer, whereby oil supplied to said oil passage duringoperation of the clutch assembly will flow outwardly through said cavityand be discharged over the inner peripheral edge of said retainer underinfluence of centrifugal force, the inner peripheral edge of saidretainer acting as a weir to control the volume of oil in said cavityduring such operation.
 13. The clutch assembly defined in claim 12,wherein said oil passage includes a generally radial passage extendingthrough the hub of said second clutch member.
 14. The clutch assemblydefined in claim 11, wherein said retainer includes a reinforcing beador flange formed around the inner peripheral edge thereof.
 15. Theclutch assembly defined in claim 11, wherein the inner surfaces of theclutch members are substantially planar.
 16. An overrunning clutchassembly comprising:a first member rotatable about an axis and includinga first surface generally normal to the axis and an axially-extendingperipheral rim portion; a second member rotatable about the axisincluding a second surface disposed in a spaced opposing relation to thefirst surface of said first member, said second member further includinga third surface thereon opposite to the second surface; an arrangementfor coupling said first member with said second member when said firstmember rotates in a first direction relative to said second member, thearrangement includinga plurality of recesses formed in each of the firstsurface of said first member and the second surface of said secondmember, each of the recesses defining an abutment shoulder, and at leastone strut, each strut having a first end for engagement with theabutment shoulders of said first member and a second end opposite thefirst end for engagement with the abutment shoulders of said secondmember, each strut including a radially-innermost portion; and anannular retainer having an outer peripheral edge portion permanentlyengaging the rim portion of said first member in fluid-tight relationtherewith, wherein said retainer includes a body portion overlying thethird surface of the second member, the body portion of said retainerextending to a location radially inward of the radially-innermostportion of each of said struts, and wherein the first surface and rimportion of the first member cooperates with the body portion of saidretainer to define an annular, radially-inwardly-opening trough forretaining a quantity of lubricating oil sufficient to substantiallyimmerse each of said struts when said lubricating oil is maintainedwithin the trough by centrifugal force.
 17. The clutch assembly of claim16, wherein the body portion of said retainer includes a first surfacewhich is engageable with the third surface of said second member tolimit axial movement of said second member away from said first member.18. The clutch assembly of claim 16, wherein said first member includesan inner cylindrical surface on the rim portion thereof, said secondmember includes an outer peripheral edge portion, and wherein the outerperipheral edge portion of said second member is telescopingly receivedwithin the inner cylindrical surface of said first member.
 19. Theclutch assembly of claim 18, wherein said first member further includesan inner peripheral edge portion and said second member further includesan inner peripheral edge portion including an axially-projecting hub,the hub having an outer cylindrical surface; and wherein the innerperipheral edge portion of said first member is telescopingly receivedabout the outer cylindrical surface of the hub.
 20. The clutch assemblyof claim 16, wherein a cavity is defined between the first surface ofsaid first member and the second surface of said second member, andwherein at least one of said members includes a lubricant-receivingchannel communicating with said cavity such that lubricating oilsupplied to said channel will flow, under the influence of centrifugalforces, radially outwardly into said cavity, axially between the outerperipheral edge portion of said second member and the inner cylindricalsurface of the rim portion of said first member, and radially inwardlybetween the third surface of said second member and the body portion ofsaid retainer.